Fingerprints are unique, convenient to be checked, and durable over the life of an individual, and therefore have become a primary means for biometric identification. After centuries of development, fingerprint recognition has becomes a very important technology of identity authentication. A fingerprint consists of ridges on the epidermis at the end of a person's finger. Two fingerprints usually have same general features, but minutia features of the two fingerprints would not be identical. Fingerprint ridges are not continuous, smooth or straight, but instead they are often terminal, bifurcated or bent. These ridge endings, bifurcations points, and bending points are referred to as “feature points”. Fingerprint recognition is a technology of performing identity authentication by comparing feature points of different fingerprints.